For example, chemicals for the electronics industry such as photo-resist are stored in a chemical container for transport, and are delivered to a factory. Such a chemical container is used in a linking configuration by which the same container is repeatedly used, or in a one way configuration by which a new container is used each time. Particularly, it is preferable to use the container in the one way mode in order not to affect the degree of purity of a high-purity chemical; however, the one way mode has an economic disadvantage. In recent years, a dual storage system-type container, which combines both of the above described modes, has been popular.
Generally, the dual storage system-type container has a bag (pouch) consisting of a flexible film which has been washed in advance. This film bag is formed of an inert material and is provided in an outer container. After the chemical is drained from the film bag, this film bag is disposed of, and a new film bag is filled with a chemical. The outer container including the joint and the like is used repeatedly.
In a way such as a dual storage system-type container, a container for liquid chemicals has been invented, which makes it possible to safely and securely drain liquid chemicals (for example, see Patent Document 1).    Patent Document 1: Japanese Unexamined Patent Application Publication No. H06-100087